>> that's the only president's election where i left the line blank. if i had been the swing vote i would have had to vote for reagan sthrks it was a turning point in his transition from the political left to the political right. >> just a few months after the election i wrote the reagan doctrine. >> reporter: it was a time magazine column. it was provocative. for a while krauthammer praised reagan on a number of foreign policy issues. he was now crediting him with a breakthrough insight that changed the calculus of the cold war. >> i realized what reagan had done without a grand master plan was to channel what at the time was called the breshnev doctrine that when we take over a country, that's ours. reagan said, no, you don't get to keep it. we're going to challenge your